Veneer dryer



Jan; 24, 1967 P. MORRIS 3,299,533

VENEER DRYER Filed Dec 20 1965 5 $heets-$heet 1 FIG. 2

IN VEN TOR.

EDWARD P. MORRIS E. P. MORRIS 3,299,533

VENEER DRYER 5 Sheets-Sheet 3 Jan. 24, 1967 Filed Dec. 20, 1963 INVEN TOR.

EDWARD P. MORRIS ATTOR EYS Jan. 24, 1967 E. P. MORRIS VENEER DRYER GIG-D zIEQ! 1 in l 0 it 20, I in I III . I i H 25 i N 20 a IGI' LI H @mlk' I? m o 0' o QIIV INVENTOR.

EDWARD I? MORRIS AT ORNEYS United States Patent 3,299,533 VENEER DRYER Edward P. Morris, Painesville, Ohio, assignor to The Coe Manufacturing Company, Painesviile, Ohio, 21 corpora tion of Ohio Filed Dec. 20, 1963, Ser. No. 333,793 1 Claim. (Cl. 34-205) The present invention relates to the drying of sheet material, especially veneer. This application is a continuation-in-part of my copending application, Serial No. 128,216, filed July 31, 1961, entitled, Veneer Dryer, and now abandoned, the disclosure of which including the specification, drawings, etc., are incorporated herein by reference.

The principal object of the invention is the provision of a novel and improved apparatus for drying veneer which will be more efficient than prior dryers used for the same purpose and wherein a gaseous drying medium is caused to flow between a plurality of vertically spaced sheets of material to be dried lengthwise thereof and caused to alternately impinge upon adjacent sides of first one sheet and then the other as it travels therebetween.

Another object of the invention is the provision of a novel and improved dryer for drying veneer as a continuous operation, and the like, comprising a housing having an elongated drying chamber with a plurality of double roller conveyors therein located one above the other, each comprising a plurality of horizontally spaced pairs of vertically aligned rolls extending crosswise of the length of the drying chamber and between which material to be dried is conveyed, and means for forcing a gaseous drying medium, such as heated air, through the drying chamber in the general direction of its length, and wherein the adjacent rollers of adjoining conveyors are offset horizontally with respect to each other so as to cause the drying medium to impinge alternately against one side and then the other of adjacent vertically spaced sheets of the material be-ing dried as the drying medium travels through the space or spaces between the material.

The invention resides in certain methods of operation constructions, and combinations and arrangements of parts and further objects and advantages of tl'e invention will be apparent to those skilled in the art to which it relates from the following description of the preferred embodiment described with reference to the accompanying drawings forming a part of this specification, in which similar reference characters designate corresponding parts, and in which:

FIG. 1 is a plan view of a veneer dryer constructed in accordance with the present invention;

FIG. 2 is a side elevational view of the veneer dryer shown in FIG. 1;

FIG. 3 is an enlarged view of a portion of FIG. 2 with parts broken away, and in section approximately on the line 33 of FIG. 1;

FIG. 4 is a view of a portion of FIG. 2 with the access door broken away, and

FIG. 5 is a view similar to FIG. 4, but of the opposite or far side of the dryer, as viewed in the other figures.

While the invention is susceptible of being embodied in a dryer having one or more decks and utilizing steam, oil, gas, etc. as the heating medium, it is herein shown and described as embodied in a five deck gas-fired dryer especially adapted for drying wet or green veneer. It is to be understood, however, that there is no intention to thereby limit the invention to the specific embodiment shown, but it is the intention to thereby cover all embodiments of the invention as expressed in the appended claims.

Referring to the drawings, the dryer shown is of the continuous type and comprises an elongated housing A, preferably, approximately thirty feet to one hundred and fifty feet long, and having a plurality of access doors 10 along opposite sides. The housing A provides an elongated drying chamber of rectangular shape in cross section through which a drying medium, such as heated air, is circulated in one direction, preferably in the direction in which the material to be dried travels through the drying chamber. The material to be dried, in the illustrated embodiment, sheets of veneer V, is carried through the dryer on a plurality of tiered or superimposed power driven conveyors, in the present instance five.

As veneer comes from the veneer lathe it is in more or less continuous sheets which are customarily cut into sheets ranging up to four feet in width plus a couple of inches allowed for trimming. Such sheets usually vary in length from four to sixteen feet in intervals of two feet plus a couple of inches allowed for trim and it is sheets of this character which the illustrated dryer is designed to dry. The invention and the dryer shown, however, are applicable to the drying of veneer sheets of any size including continuous sheets.

The veneer may be fed into the wet end of the dryer in any convenient manner. When noncontinuous sheets of veneer are being dried they are preferably fed into the dryer in such a manner that the adjacent ends of following sheets in any one deck adjoin or substantially adjoin one another and such that each deck of the dryer is full or substantially full transversely of the dryer. In other words, the dryer is preferably maintained full or substantially full of veneer with the veneer dividing the dryer into a plurality of horizontal air chambers or ducts, one of which is below the bottom conveyor deck, others of which are intermediate the conveyor decks and one of which is above the upper conveyor deck. This facilitates the maintenance of the desired air flow pattern through the dryer as will be hereinafter more specifically referred to.

The decks or conveyors of the dryer are located one above the other, are preferably spaced apart vertically approximately ten inches to eighteen inches, are of the double roller type and since they are substantially alike or duplicates of one another merely the lower deck will be described in detail. The duplicate or corresponding parts of the other decks will be designated by the same reference characters with a prime, double prime, triple prime, etc., mark applied thereto to designate the second, third, fourth, etc. decks, respectively.

The lower deck of the dryer comprises a multiplicity of horizontally spaced pairs of lower or bottom and upper rollers or rolls 15, 16, the latter of which are located directly above the former. The pairs of rollers 15, 16 are spaced horizontally from one another such that their center to center distances are approximately six inches to twelve inches and each pair is identical and is supported and driven in the same manner. The rolls of each pair are alike, are preferably approximately three inches to five inches in diameter and have journal sections at opposite ends by means of which they are rotatably supported in brackets 17, 1 3 at opposite ends thereof. The brackets 17, 18 are deta-chably bolted to elongated angular-shaped frame members 20, 21 extending lengthwise of the. dryer along opposite sides thereof. The reduced J journal projections of the lower rolls project through cylindrical apertures in the brackets 17, 18 at opposite ends thereof and are thus supported for rotation about fixed axes. The journal projections at opposite ends of the upper rolls 16 project through vertically elongated slots in the bracket-s, which slots permit the upper roll 16 of each pair of rolls to move away from the lower roll associated therewith upon the entrance of veneer therebetween. The weight of the upper roll 16 normally maintains it in contact with either the roll 15 therebelow or the veneer passing between the rolls.

The lower roll 15 of each pair is driven by a sprocket chain extending through the dryer from a drive rig or unit D located adjacent to one end of the dryer to an automatic chain tightener unit T, located adjacent to the other end of the dryer. The drive rig or unit D is a commercial construction and will not be described in detail. Suffice it to say that it includes an electric drive motor 27 connected to a variable speed transmission 28. The automatic chain tightener is also of commercial con struction and will not be described in detail. The upper reach of the sprocket chain engages the upper part of sprocket wheels 39, keyed to the ends of the journal sections of the lower rollers 15 projecting to the outside of the brackets 17. From'the chain tightener, the lower reach of the sprocket chain passes underneath the sprocket wheels 39 back to the drive rig. Suitable brackets 35 are provided for holding the upper reach of the sprocket chain in engagement withthe sprocket wheels and for supporting the lower reach of the sprocket chain in its return to the drive rig. The upper roll of each pair is driven at substantially the same speed as the lower roll by interengaging gear wheels 36, 37, keyed to the journal projections of the rolls 15, 16 at the far side of the dryer. These gear wheeis are so constructed that they remain in mesh even though the upper roll 16 may Operate a short distance from the lower roll as the veneer passes therebetween. The conveyors extend through an entrance section B at the wet end of the dryer and a cooling section C at the dry end of the dryer, the upper rolls 16, howcver, are usually omitted from the portions of the conveyor which are located in the entrance section B of the dryer. Any suitable roll arrangement, including the arrangement shown herein may be used in the discharge or cooling end of the dryer.

The second deck of the dryer is similar in construction to the first or lower deck, just described, except for the fact that the pairs of rolls thereof are spaced hori zontaily between the pairs of rolls of the first deck. The same is true of the other decks which are adjacent to one another. In the dryer shown, the pairs of rolis of the first, third and fifth decks are vertically aligned, as are the pairs of rolls of the second and fourth decks, and the pairs of rolls of each deck are midway between the rolls of adjacent decks. However, other suitable arrangements and/or spacings may be employed. The pairs of rolls of each deck are spaced horizontally from one another preferably approximately six inches to twelve inches and the distance between the decks is preferably approximately ten inches to eighteen inches. The optimum arrangement of rolls is such that the air space between adjoining decks, when the decks 'are load-ed with veneer, is more or less uniform.

Drying fluid, in the present instance heated air, is circulated and recirculated through the drying chamber by a plurality of electric motor driven centrifugal fans 50, 51 located on the top of the dryer housing proper. The suction sides of the fans are connected by manifolds 52, 53 to the dry end of the dryer and the fans discharge into a recirculated air duct in the dryer housing above the drying chamber. The other end of the air duct is connected to the feed or wet end of the dryer by manifolds 55, 56 similar to that in which the suction side of the fan is connected to the exit end of the drying chamber.

The air passing through the air duct is directly heated or reheated by a plurality of gas burners E therein. The dryer may be provided with a vent stack 60 with or without a damper therein for exhausting vapors, as desired. Cool air is circulated through the cooling section C of the dryer by an electric motor driven fan 61. The reference character 62 designates an air seal section having an electric motor driven fan 63.

As indicated in FIG. 3, the veneer since it is impervious to air divides the drying chamber into a plurality of superimposed air passages through which the drying medium, or air, is caused to move from left to right and as the air moves through the respective passages between the vertically spaced decks of veneer it is deflected .by the rolls of the decks alternately against the upper side of one layer or deck of veneer and the underside of the layer or deck of veneer immediately thereabove. In the case of thebottom and upper decks where there are no rolls to deflect the air into engagement with the underside of the veneer in the lower deck and the upper side of the veneer in the upper deck, corrugated-like bottom and upper bafiies 65, 66 or some other suitable arrangement may be employed. Alternatively, dummy rolls similar to the other rolls could be substituted for the bafiles shown with the dummy rolls interposed horizontally between the rolls of the deck adjacent thereto.

With the construction shown it will be apparent that the air traveling through the dryer will alternatively impinge against the veneer of one deck and then another and that its velocity where it contacts the veneer may be relatively high, depending on the diameters of the rolls and their spacing.

While a particular dryer constructed in accordance with the present invention has been herein shown and described in considerable detail, it is to be understood that the invention is not limited to the construction shown nor to a dryer wherein the air moves thercthrough in the same direction as the material being dried. Obviously the air could be caused to flow in the opposite direction. From the foregoing it is believed that the objects of the invention theretofore enumerated and others have been accomplished and that there has been provided a novel and improved multiple deck, double roller veneer dryer in which the conveyor rolls serve the dual purpose of conveying through the dryer the veneer or veneers to be dried and of deflecting the hot circulating air in the dryer against the veneer being conveyed through the dryer.

Commercial dryers constructed in accordance with the present invention and used for drying veneer have been found to be more efficient than prior art dryers used for the same purpose.

Having thus described my invention, I claim:

In apparatus for drying veneer, a housing having an elongated drying chamber therein, a plurality of discrete power driven horizontal conveyors in said drying chamber extending lengthwise thereof and positioned one above the other for moving material to be dried through said drying chamber along predetermined paths of travel spaced approximately ten to eighteen inches apart, each of said conveyors comprising a plurality of pairs of rolls extending crosswise of the length of said drying chamber the diameters of which are approximately three to five inches, each pair of said rolls comprising a top and a bottom roll located one directly above the other and above and below the path of travel of the material conveyed by the respective conveyor of which they are a part, said pairs of rolls being spaced along the respective conveyors of which they are a part such that their center distances are approximately six to twelve inches, said pairs of rolls of adjacent conveyors being offset horizontally approximately midway between one another, and means for introducing air into said chamber adjacent to one end thereof laterally of the roll axis and exhausting it adjacent to the other end of said chamber, whereby the air 5 is caused to impinge upon one side of a veneer sheet 1,834,962 and then upon an adjacent side of another veneer sheet 2,342,007 as it travels therebetween. 2,726,459 2,758,386 References Cited by the Examiner 5 2,996,811

UNITED STATES PATENTS 1,642,928 9/1927 Kocha 34205 X 1,675,284 6/1928 Vance 34205 X Moore 34-205 Morse 3431 X Morris 34205 Cobb 34205 X Loeohl 34205 FREDERICK L. MATTESON, JR., Primary Examiner.

C. R. REMKE, Assistant Examiner. 

